1 Web Services for Semantic Interoperability and Integration Tim Finin University of Maryland, Baltimore County Dagstuhl, 20 September Joint work with many colleagues and students.  This work was partially supported by DARPA contract F , NSF grants CCR and IIS and grants from IBM, Fujitsu and HP.

UMBC an Honors University in Maryland 2 Overview The question The question What role will web services play in support of semantic interoperability and integration (SII) ? My answer My answer Illustration using two examples drawn from our work Illustration using two examples drawn from our work

UMBC an Honors University in Maryland 3 My Answer (1) Agents fill many useful roles for SII (2) On the web, web services play the role of agents (3) The web is consuming all IT (4) Therefore web services will replace agents in systems doing SII

UMBC an Honors University in Maryland 4 Agents are useful for SSI Agents are Agents are Agent roles for SII include Agent roles for SII include Discovery of ontologies, terms (e.g., class, property), and individuals Discovery of ontologies, terms (e.g., class, property), and individuals Translation services Translation services Dynamic computing alignments and matches Dynamic computing alignments and matches Meaning negotiation Meaning negotiation Reasoning services Reasoning services …

UMBC an Honors University in Maryland 5 web services  agents On the web, there’s pressure to push all programs behind web service APIs On the web, there’s pressure to push all programs behind web service APIs It doesn’t make much difference if agents communicate via KQML+KIF, FIPA, or OWL+web services It doesn’t make much difference if agents communicate via KQML+KIF, FIPA, or OWL+web services We want to be at a level of abstraction involving beliefs, desires, intentions, plans, goals, etc. We want to be at a level of abstraction involving beliefs, desires, intentions, plans, goals, etc. SO, if the price of admission is to use SOAP and WSDL, we’ll pay it SO, if the price of admission is to use SOAP and WSDL, we’ll pay it

UMBC an Honors University in Maryland 6 The Web Is like the Blob, consuming all in it’s path Is like the Blob, consuming all in it’s path Resistance is futile Resistance is futile More seriously… More seriously… it promotes sharing, building on other’s content, offering your content for building upon, decentralization, community development and evolution, common identifiers (URIs), has a working infrastructure, etc. These are significant advantages These are significant advantages

UMBC an Honors University in Maryland 7 Example: Security and Trust for Semantic Web Services Semantic web services are web services described using OWL-S Semantic web services are web services described using OWL-S Policy-based security infrastructure Policy-based security infrastructure Advantages of using policies: Advantages of using policies: Expressive -- can be over descriptions of requester, service & context Expressive -- can be over descriptions of requester, service & context Authorization: Rules for access control Authorization: Rules for access control Privacy: Rules for protecting information Privacy: Rules for protecting information Confidentiality: Cryptographic characteristics of information exchanged Confidentiality: Cryptographic characteristics of information exchanged Policies + Semantic Web Services

UMBC an Honors University in Maryland 8 Example Mary is looking for a reservation service Mary is looking for a reservation service Functional service requirements Functional service requirements foaf identity description foaf identity description Confidentiality policy Confidentiality policy BravoAir is a reservation service BravoAir is a reservation service OWL-S description OWL-S description Authorization policy (e.g., Only users belonging to the same project as John can access the service) Authorization policy (e.g., Only users belonging to the same project as John can access the service) Privacy policy Privacy policy The CMU matchmaker is an agent that finds and recommends services The CMU matchmaker is an agent that finds and recommends services

UMBC an Honors University in Maryland 9 Mary Mary Smith Mary Smith <foaf:title>Ms</foaf:title><foaf:firstName>Mary</foaf:firstName><foaf:surname>Smith</foaf:surname> </foaf:Person></rdf:RDF>

UMBC an Honors University in Maryland 10 Bravo Policy <constraint:SimpleConstraint rdf:about="&bravo- policy;GetJohnProject" constraint:subject="&john;John" constraint:predicate="&foaf;currentProject" constraint:object="&bravo-policy;var2"/> <constraint:SimpleConstraint rdf:about="&bravo- policy;SameProjectAsJohn" constraint:subject="&bravo-policy;var1" constraint:predicate="&foaf;currentProject" constraint:object="&bravo-policy;var2"/> <constraint:And rdf:about="&bravo- policy;AndCondition1" constraint:first="&bravo-policy;GetJohnProject" constraint:second="&bravo- policy;SameProjectAsJohn"/> ………

UMBC an Honors University in Maryland 11 How it works BravoAir Web service Mary Matchmaker and Reasoner URL to foaf desc + query request Bravo Service OWL-S Desc

UMBC an Honors University in Maryland 12 How it works Mary’s query = Bravo Service ? YES Extract Bravo’s policy Does Mary meets Bravo’s policy ? Authorization enforcement complete Mary BravoAir Web service <constraint:SimpleConstraint rdf:about="&bravo-policy;SameProjectAsJohn" constraint:subject="&bravo-policy;var1" constraint:predicate="&foaf;currentProject" constraint:object="&bravo-policy;var2"/> Is the constraint true when var2 = var1 = sec/MaryProfile.rdf <constraint:SimpleConstraint rdf:about = "&bravo-policy;GetJohnProject” constraint:subject="&john;John" constraint:predicate="&foaf;currentProject" constraint:object="&bravo-policy;var2"/> var2 =

UMBC an Honors University in Maryland 13 Google has made us smarter Google has made people smarter Google has made people smarter Software agents need something similar to maximize their use of information on the semantic web. Software agents need something similar to maximize their use of information on the semantic web.

UMBC an Honors University in Maryland 14 Swoogle: Google for SWDs Swoogle is a crawler based search & retrieval system for semantic web documents. It discovers them, builds a DB of metadata & relations, stores them in a triple store and their source in an IR system. Current Status ~190K SW documents ~1% ontologies ~33M triples ~60K classes ~50K properties ~5M values Swoogle may provide the corpus of ontologies and data that use them desired by Natasha e.g., answering queries like: Find all documents that map between O1 and O2 What classes are owl:sameAs C What values are used for properties P1 and P2? Find all OWL-S service instances

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UMBC an Honors University in Maryland 16 The Celebrity Couple SemanticWebSemanticWebSoftwareAgentsSoftwareAgents In 2001, Geek Gossip gushed “The semantic web will provide content for internet agents, and agents will make the semantic web “come alive”. Looks like a match made in Heaven!”

UMBC an Honors University in Maryland 17 Love is Fickle SemanticWebSemanticWeb Web Services In 2003, the Semantic web was seen everywhere in the company of a new friend, web services. Software agents was recently arrested for DUI and assaulting a police officer.

UMBC an Honors University in Maryland 18 Example policies Authorization Authorization Policy 1: Stock service not accessible after market closes Policy 1: Stock service not accessible after market closes Policy 2: Only LAIT lab members who are Ph.D. students can use the LAIT lab laser printer Policy 2: Only LAIT lab members who are Ph.D. students can use the LAIT lab laser printer Privacy/Confidentiality Privacy/Confidentiality Policy 3: Do not disclose my my SSN Policy 3: Do not disclose my my SSN Policy 4: Do not disclose my home address or facts from which it could be easily discovered Policy 4: Do not disclose my home address or facts from which it could be easily discovered Policy 5: Do not use a service that doesn’t encrypt all input/output Policy 5: Do not use a service that doesn’t encrypt all input/output Policy 6: Use only those services that required an SSN if it is encrypted Policy 6: Use only those services that required an SSN if it is encrypted

UMBC an Honors University in Maryland 19 SWOOGLE 2 SWD Metadata Web Service Web Server SWD Cache The Web Candidate URLs Web Crawlers SWD Reader IR analyzerSWD analyzer Swoogle 2 Architecture Human users Intelligent Agents discovery digest analysis service Ontology Dictionary Swoogle Search Swoogle Statistics